Condenser scoop



arch 24, 1936}. A. l. PONOMAREFF CONDENSER SCOOP Filed May 25, 1935 2 Sheets-Sheet l .imili DKIBIQIL j F F M H M m 0 P L m w H X E L INVENTOR WITNESSES:

ATTORN EY Patented Mar. 24, 1936 PATENT OFFICE CONDENSER SCOGP Alexander Ivan Ponomareff, Ridley Park, Pa.,

assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 25, 1935, Serial No. 23,530

8 Claims.

My invention relates to scoops for circulating condensing water through marine condensers and it has for an object to provide apparatus of this character which shall serve withimproved efficiency when the ship is operated astem.

While scoops are generally satisfactory for circulating condenser water of a marine condenser when the ship is operated ahead, losses are encountered with astern operation; and these losses increase with increase in astern speed. The loss may be expressed by the hydraulic formula:

2 Loss C feet of water (1) where: C-dimensionless coefficient.

V-average velocity through scoop-feet per second. g-accelemtion due to gravity-feet per second, per sec.

The loss must be overcome by the circulating water pump; and, as the'scoop is arranged at the suction side of the pump, the loss necessarily entails a much higher'suction lift.

As the result of experimentation, I find that the loss in question is very largely due to a sharp change in direction of flow in entering the scoop inlet, particularly when operating at high astem speeds. I furthermore find that the provision of a deflector or shield spaced a suitable distance from the astern side of the scoop inlet facilitates entrance of water'into the scoop andreduces'the loss in question. Apparently, such a plate or deflector induces such condition and directions of the stream lines that the water may enter the scoop much easier. Accordingly, a further object of my invention is to provide a scoop for a marine condenser wherein a shield protrudes from the skin of the ship at the astern side of the scoop inlet so as L facilitate the entrance of water into the scoop when the ship is operated astern.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is-a diagrammatic view of a portion of a ship having my improved scoop arrangement applied thereto;

Fig. 2 is a diagrammatic view showing the relative arrangement of the scoop inlet and the shield;

Fig.3 isa side elevational view of the shield;

Figs. 4, 5, 6, and Tare diagrammatic views illustrative of principles involved in my invention; and

Figs. 8 and 9 show modified forms of deflectors.

As hereinbefore pointed out, the loss in the ordinary scoop when the ship is operated astern is equal to feet of water. Fig. 4 shows the variation in the coefficient C with respect to variation in quantity of water circulated at an astern speed of approximately 20 knots. From this curve. it will be noted that the coefficient C decreases with increase in the quantity of water "circulated, While the loss of head in the scoop increases because of increase in velocity of water through the'scoop as it will be noted from Fig. 7 which shows the loss of head in the scoopfor various flow of circulating'water when ship is running astern at'approximately 20 knots. It is apparentfrom Fig. '7 that the loss in the scoop not only imposes additional pumping head but also limits the pump capacity on account of excessive suction lift produced.

In Fig. 5, the diagram shows the relation of the coefficient C to protrusion of the shield from the ships skin. From this diagram, it will be seen that the greatest efiect, so far as reducing the coeflicient and therefore the loss in the scoop is concerned, is secured by the portion of the shield or plate adjacent to the ships skin, the efiectiveness in reduction of the 'coeflic'ient becoming less and less with increase in distance from the skin. For example, with 30 or 40% of scoop diameter protrusion, very substantial reduction in, the coeflicient is secured without excessive control extent from the hull skin.

Diagrammatic Fig. 6 shows the relation of the coefficient"C with respect to length of the shield or plate athwartship,' the length being expressed in percentage of scoop diameter. Here again, it will be noted-that any length of shielding is effective, but that the advantage tends to diminish with increase in length. If the shield is made of the length equal to the scoop diameter, then the coefficient is reduced to approximately 2 as compared to if shield were not provided. While the maximum advantage could be secured with a length exceeding the scoop diameter, yet, other disadvantages in consequence of excessive length make the latter undesirable.

Fig. '7 indicates the loss of head at various flows/through the scoop when the ship is moving at about 20- knots astern.

that, for a given size of scoop, as the coefficient is made smaller, the head loss is reduced proportionately. Fig. 5 shows that the maximum advantage in reducing the coefficient C is secured by protrusion of the shield from the skin of the ship a distance of the order of 30 or 40% of the scoop diameter; andFig. 6 shoWS that the maximum advantage, so far as any length of the shield is concerned, is secured by a length of the'order of 100% of the scoop diameter. grams, it will be apparent that a shield having athwartship length equal to the scoop diameter and having an outward protrusion of between 30 and 40% include the most effective portions of these dimensions so far as'jreduction in the coefficient is concerned.

Referring now to Figs. 1, 2, and 3, in Fig. 1, I show a marine condenser Hl having circulating water supplied thereto by means of a scoop II, when the ship is operated in the ahead direction indicated by the arrow. The scoop ll extends through the skin I 2 of the ship and relative motion ofthe ship with respect to water induces flow.

The scoop ll supplies water through the conduit l3 to the condenser inlet water box I4. A pump [5 isassociated with the conduit and it assures flow of cooling Water when the ship is propelled at low speeds or when operating astern.

While the arrangement, described is highly effective for ahead operation, losses are encoun-' tered when operating astern, and such losses, not only increase the work of maintaining circulation, but they impose additional suction lift on the pump. Experiments indicate that the scoop head loss is induced by a disadvantageous direction of flow of the water relatively to the ship, when going astern, giving a large value of dimensionless co-v .eflicient Cfin the head loss equation,

. V2 Loss C Accordingly, not only have I provided a. shield l6 at the astern side of the scoop inlet to reduce the loss of head when going astern, but I have determined factors of the shield which control the magnitude of the coeflicient. The shield or plate [6, projects outwardly from the skin of the ship at the asternside of the scoop'inlet and it is spaced a suitable distance rearwardly of the latter, the shield apparently inducing a hydraulic jump, which permitswater to enter the scoop with very much reduced loss. p

The deflector or shield may be used, with advantage with scoops provided with or without lips. In Fig. 1, the scoop has a conventional lip portion l] at the astern side of the inlet.

Preferably, the deflector or shield, lfiextends athwartship a distance approximating the scoop diameter, it being apparent, from Fig. 6, that very substantial reduction in the coefficient C may be effected with a shield of this length, that is, a. shield of this length'maybe employed to effect very substantialportion of thereduction in the coefi'icient possible with'increased length of Sofar as protrusion. of the shieldfrom the skin of the ship is concerned, this may be advantageously about of the diameter of the scoop, this distance effecting the major portion of the possible reduction in the value of the coeificient by increasing the protrusion. w I r Y The deflector plate or shield ;l6 may be rounded; as-indicated at I 8, to' avoid the presence From these diae of square corners, the rounded portions leaving a sufficient length of deflector or shield of maximum protrusion where most effective, for, it will be apparent that the scoop boundary defines the smallest angle with respect to the skin of the ship at the astern side, such angle increasing from the mid-point at the back until right angles are defined at the sides. The acute angular portion of the boundary is taken care of by the portion of the shield of maximum protrusion, the rounded ends I! being effective for portions of the inlet whereithe boundary angle becomes larger.

Where the scoop is provided with a lip at the astern side, and as shown in Fig. 1, I prefer to have the deflector, or shield made of such size that, if the lip is projected thereon, the projection will just include the boundary of the deflector. r

In Fig. 8, I show a deflector 20, operating similarly to the deflector [6, but which is constructed to fill the space back of the lip I I. Fig. 9 is similar to Fig. 8, but including the added feature of a fillet deflector 2| for deflecting submerged objects. While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are set forth in the appended claims. 1 y .1

What I claim is: 1. The combination with a ship having a skin and a condenser for its power plant, the condenser having an inlet water box, of circulating water supply conduit means'communicating' with the inlet water box, a scoop connected to said conduit means and'extendin'g through the skin of the ship and effective, when the ship is going ahead above a predetermined speed, to causeflow of water through the conduit means and the condenser, a pump associated with the conduit means to assure adequate flow when operating ahead below said predetermined speed and when operating astern, and means for reducing the head loss so as to facilitate flow when operating astern including a shield disposed astern of the scoop entrance and extending outwardly from said skin.

- 2. The combination with a ship having a skin and a condenser for its power plant, the condenser having an inlet water box, of circulating water supply conduit means communicating with the inlet water box, a scoop connected tosaid conduit means and extending through the skin of the ship and effective, when the ship is going ahead above a predetermined speed, to cause flow of water through the conduit means and the condenser, a pump associated with the conduit means to assure adequate flow when operating ahead below said predetermined speed and when operating astern, the boundary of the scoop inlet including a lip at the astern side thereof, said lip extending outwardlyfrom said skin, and a shield disposed at theaste'rn side of the lip and serving, when the shipis operated astern, to reduce the head loss in the scoop. n

3. The combination with a ship having askin and a condenser for its power plant, the condenserhavin'g an inlet water box, of circulating water supplied conduit means communicating with theinlet water box, a scoop connected to said conduit means and extending through the skin ofthei -ship and-effective, when the ship going ahead above a predetermined speed-"to cause flow of water through the conduit means and the condenser, a pump associated with the conduit means to assure adequate flow when operating ahead below said predetermined speed and when operating astern, said scoop having its astern side projecting outwardly from the skin of the ship to form a lip and having its forward side arranged substantially flush with said skin, and a deflector extending outwardly from the skin of the ship at the astem side of the lip and serving to facilitate the flow of water through the scoop when the ship is operated astern.

4. The combination with a ship having a skin and a condenser for its power plant, the condenser having an inlet water box, of circulating water supply conduit means communicating with the inlet water box, a scoop connected to said conduit means and extending through the skin of the ship and effective, when the ship is going ahead above a predetermined speed, to cause flow of water through the conduit means and the condenser, a pump associated with the conduit means to assure adequate flow when operating ahead below said predetermined speed and when operating astern, and a shield disposed at the astem side of the scoop and serving to facilitate the flow of water through the latter when the ship is operated astern, said shield being comprised by a plate which extends athwartship with respect to the skin of the ship and outwardly from the latter.

5. The combination as claimed in claim 4 wherein the shield plate is attached to the skin of the ship and is of a length substantially equal to the diameter of the scoop.

6. The combination as claimed in claim 4 wherein the shield plate has a length adjacent to the skin of the ship substantially equal to the scoop diameter and has an outer approximately convex edge.

'7. The combination as claimed in claim 4 wherein the shield plate is of a length adjacent to the skin of the ship substantially equal to the diameter of the scoop and which protrudes outwardly from the skin of the ship a maximum distance of the order of one-third the diameter of the scoop inlet;

8. The combination with a ship having a skin and a condenser for its power plant, the condenser having an inlet water box, of circulating water supply conduit means communicating with the inlet water box, a scoop connected to said conduit means and extending through the skin of the ship and effective, when the ship is going ahead above a predetermined speed, to cause flow of water through the conduit means and the condenser, a pump associated with the conduit means to assure adequate flow when operating ahead below said predetermined speed and when operating astern, said scoop having a lip arranged at the astern side of its inlet, a shield arranged at the astern side of said lip and protruding outwardly from the skin of the ship, the area of the lip projected on the shield substantially coinciding with the area of the latter and the shield serving to facilitate the flow of water through the scoop when the ship is operated astern.

ALEXANDER IVAN PONOMAREFF. 

